Blame Benedict Cumberbatch for not getting a Sherlock/Doctor Who crossover

Given that Sherlock and Doctor Who share a showrunner in Steven Moffat, it would seem that a crossover episode isn’t just the stuff of daydreams. Some might argue it would even be the least he could do, given how long fans are being made to wait for future Sherlock episodes.
At a Q&A at the Doctor Who premiere in Cardiff this weekend, Moffat voiced his theoretical support for such a crossover—but then said it would never happen, blaming Sherlock stars Benedict Cumberbatch, Martin Freeman, and Mark Gatiss, as well as fellow producer Sue Vertue. “They’re all in the way,” Moffatt said. “I’m not the killjoy, it’s that lot. It’s probably not going to happen.” (Mark Gatiss, who plays Sherlock’s brother Mycroft, has already guest-starred as two different characters on Doctor Who and voiced a third.)